Pathogenesis of paracoccidioidomycosis: a model based on the study of 46 patients

Pathogenesis and Classification of Paracocidioidomycosis: New Insights From Old Good Stuff

Different classifications of paracoccidioidomycosis emerged since its discovery in 1908, culminating in the proposition of a simplified and consensual one in 1987. However, by revisiting these classifications, case reports, or case series from which the authors based their own, we found many patients who did not fit in either the 1987 classification or in the correspondent natural history/pathogenesis view. In this report, the concepts of paracoccidioidomycosis infection, primary pulmonary paracoccidioidomycosis (PP-PCM), and other subclinical forms of PCM are reassessed. A classification is proposed to encompass all these subtle but distinct outcomes. I suggest a continuum between the PP-PCM and the overt chronic form of disease, and not the current view of quiescent foci, frozen in time and suddenly reactivated for unknown reasons. Failure to fully resolve the infection in its initial stages is a conceivable hypothesis for the chronic form. The proposed clinical classification might offer new insights to better characterize and manage PCM patients.

Eighty Years of Mycopathologia: A Retrospective Analysis of Progress Made in Understanding Human and Animal Fungal Pathogens

Mycopathologia was founded in 1938 to 'diffuse the understanding of fungal diseases in man and animals among mycologists.' This was an important mission considering that pathogenic fungi for humans and animals represent a tiny minority of the estimated 1.5-5 million fungal inhabitants on Earth. These pathogens have diverged from the usual saprotrophic lifestyles of most fungi to colonize and infect humans and animals. Medical and veterinary mycology is the subdiscipline of microbiology that dwells into the mysteries of parasitic, fungal lifestyles. Among the oldest continuing scientific publications on the subject, Mycopathologia had its share of 'classic papers' since the first issue was published in 1938. An analysis of the eight decades of notable contributions reveals many facets of host-pathogen interactions among 183 volumes comprising about 6885 articles. We have analyzed the impact and relevance of this body of work using a combination of citation tools (Google Scholar and Scopus) since no single citation metric gives an inclusive perspective. Among the highly cited Mycopathologia publications, those on experimental mycology accounted for the major part of the articles (36%), followed by diagnostic mycology (16%), ecology and epidemiology (15%), clinical mycology (14%), taxonomy and classification (10%), and veterinary mycology (9%). The first classic publication, collecting nearly 200 citations, appeared in 1957, while two articles published in 2010 received nearly 150 citations each, which is notable for a journal covering a highly specialized field of study. An empirical analysis of the publication trends suggests continuing interests in novel diagnostics, fungal pathogenesis, review of clinical diseases especially with relevance to the laboratory scientists, taxonomy and classification of fungal pathogens, fungal infections and carriage in pets and wildlife, and changing ecology and epidemiology of fungal diseases around the globe. We anticipate that emerging and re-emerging fungal pathogens will continue to cause significant health burden in the coming decades. It remains vital that scientists and physicians continue to collaborate by learning each other's language for the study of fungal diseases, and Mycopathologia will strive to be their partner in this increasingly important endeavor to its 100th anniversary in 2038 and beyond.

Therapeutic Response in Adult Patients with Nonsevere Chronic Paracoccidioidomycosis Treated with Sulfamethoxazole-Trimethoprim: A Retrospective Study

According to the Brazilian Consensus on Paracoccidioidomycosis (PCM), itraconazole is the drug of choice for treatment. However, the combination of sulfamethoxazole and trimethoprim (SMX-TMP) is most commonly used in clinical practice because of its higher availability in the public health services. The aims of this study were to evaluate the therapeutic response of patients with nonsevere chronic PCM to SMX-TMP and highlight the factors related to treatment failure. An adequate therapeutic response was defined as completely improved disease signs and symptoms after medication use for a minimum of 6 months, followed by normalized hematological and biochemical changes, radiological improvements, and negative mycological examination findings. Medical records were analyzed for 244 patients with nonsevere chronic PCM who were treated between 1998 and 2014. In total, 41.9% of the patients had PCM for ≥ 8 months. Seven (2.9%) patients were coinfected with human immunodeficiency virus (HIV). The median (25%, 75% percentiles) treatment duration was 21 (10, 25) months. Adequate treatment adherence was reported by 68.3% of patients. In addition, 73.6% of patients exhibited an adequate therapeutic response. The majority (82.6%) of patients who were treated with SMX-TMP for > 24 months displayed an adequate therapeutic response, and the frequency of adequate therapeutic response gradually decreased as the duration of treatment decreased. Treatment nonadherence (P < 0.001) and PCM-HIV coinfection (P = 0.019) were factors associated with therapeutic failure. The study results support the good efficacy of SMX-TMP. Attention should be given to PCM-HIV coinfection, emphasizing the concern of a higher risk of PCM therapeutic failure in these patients.

Endemic paracoccidioidomycosis: relationship between clinical presentation and patients' demographic features

Paracoccidioidomycosis (PCM) is a systemic fungal disease endemic to Latin America and characterized by two clinical presentations, i.e., patients develop either acute/subacute or chronic clinical manifestations. The differences in clinical presentations are mainly dependent on the host immune response, but may also be related to demographic characteristics of some patients. In this retrospective study, 1,219 PCM cases treated between 1970 and 2009 in a university medical center, located in southeastern Brazil, were analyzed according to their clinical and demographic features. The most affected anatomical sites were lungs (63.8%) and oral mucosa (50.0%), with increasing involvement of these sites in accord with the age of the patients. Generalized lymphadenopathy (28.1%) and skin lesions (29.6%) were more frequent on the first decades of life. Involvement of the larynx (16.1%), gut (7.5%), spleen (4.7%), central nervous system (3.4%), bones and joints (2.2%), and adrenal (2.1%) were also variable according to the age of the host. The acute/subacute form of the disease accounted for 26.4% of PCM cases and, on a multivariate analysis, was inversely associated with aging (OR = 0.8 per year, P < 0.001), and directly associated with female sex (OR = 7.2, P < 0.001), mixed black and white racial background (OR = 2.3, P < 0.001) or black skin color (OR = 4.6, P < 0.001). Based on these findings, we have shown that host immune response, as well as age, gender and ethnicity may influence the clinical presentation of PCM.

Immunological basis for the gender differences in murine Paracoccidioides brasiliensis infection

This study aimed to investigate the immunological mechanisms involved in the gender distinct incidence of paracoccidioidomycosis (pcm), an endemic systemic mycosis in Latin America, which is at least 10 times more frequent in men than in women. Then, we compared the immune response of male and female mice to Paracoccidioides brasiliensis infection, as well as the influence in the gender differences exerted by paracoccin, a P. brasiliensis component with carbohydrate recognition property. High production of Th1 cytokines and T-bet expression have been detected in the paracoccin stimulated cultures of spleen cells from infected female mice. In contrast, in similar experimental conditions, cells from infected males produced higher levels of the Th2 cytokines and expressed GATA-3. Macrophages from male and female mice when stimulated with paracoccin displayed similar phagocytic capability, while fungicidal activity was two times more efficiently performed by macrophages from female mice, a fact that was associated with 50% higher levels of nitric oxide production. In order to evaluate the role of sexual hormones in the observed gender distinction, we have utilized mice that have been submitted to gonadectomy followed by inverse hormonal reconstitution. Spleen cells derived from castrated males reconstituted with estradiol have produced higher levels of IFN-γ (1291±15 pg/mL) and lower levels of IL-10 (494±38 pg/mL), than normal male in response to paracoccin stimulus. In contrast, spleen cells from castrated female mice that had been treated with testosterone produced more IL-10 (1284±36 pg/mL) and less IFN-γ (587±14 pg/mL) than cells from normal female. In conclusion, our results reveal that the sexual hormones had a profound effect on the biology of immune cells, and estradiol favours protective responses to P. brasiliensis infection. In addition, fungal components, such as paracoccin, may provide additional support to the gender dimorphic immunity that marks P. brasiliensis infection.

Cavitary pulmonary disease

A pulmonary cavity is a gas-filled area of the lung in the center of a nodule or area of consolidation and may be clinically observed by use of plain chest radiography or computed tomography. Cavities are present in a wide variety of infectious and noninfectious processes. This review discusses the differential diagnosis of pathological processes associated with lung cavities, focusing on infections associated with lung cavities. The goal is to provide the clinician and clinical microbiologist with an overview of the diseases most commonly associated with lung cavities, with attention to the epidemiology and clinical characteristics of the host.

Prostaglandin E(2) production by high and low virulent strains of Paracoccidioides brasiliensis

The production of prostaglandins (PGs) during fungal infections could be an important suppressor factor of host immune response. Host cells are one source of prostaglandin E(2) (PGE(2)); however another potential source of PGE(2) is the fungal pathogen itself. Thus, both host and fungal PGE2 production is theorized to play a role in pathogenesis, being critical for growth of the fungus and to modulate the host immune response. The purpose of this work was to investigate if high and low virulent strains of Paracoccidioides brasiliensis have the capacity to produce PGE(2) in vitro, and if this production was related to the fungal growth. The results demonstrated that both strains of P. brasiliensis produce high levels of PGE(2) and the treatment with indomethacin, a cyclooxygenase inhibitor, significantly reduced the production of this mediator, as well as the viability of the fungus. Thus, our data indicate that PGE(2) is produced by P. brasiliensis by a cyclooxygenase-dependent metabolic pathway, and its production is required for fungal survival. This discovery reveals an important factor that has potentially great implications for understanding the mechanisms of immune deviation during infection.

Clinical Evolution of Paracoccidioidomycosis in 38 Children and Teenagers

Paracoccidioidomycosis (PCM) in children is rare, and its clinical progression is not clearly understood. The admission and post-admission clinical records of 38 children and teenagers aged up to 14 were studied who had been under treatment for 24-30 months. It is a consecutive case series, 17 retrospective and 21 prospective, from 1977 to 2000, admitted before and after 1990, respectively. The main clinical presentations were lymphatic, abdominal and cutaneous involvement, and fever. The alterations which disappeared more slowly were lymphadenomegaly, hepatomegaly, splenomegaly, and osteoarticular pain. Poor intestinal absorption, esophageal varices and splenic calcification were observed before treatment and persisted as sequelae. There was a satisfactory response to initial treatment in 56.7% of cases. Half the patients became asymptomatic in the ninth month of treatment, and 17+/-8% of cases presented with at least one symptom of the disease after 30 months of treatment. There were five deaths, and treatment failure was frequent and associated in part with the irregular use of antifungal. Treatment with ketoconazole was safe and effective. PCM is a serious systemic disease with slow evolution and high lethality, requiring treatment maintenance for a minimum of 24 months with careful and prolonged follow-up. Studies are necessary to evaluate the efficacy of different antifungals and the ideal treatment length for children with PCM.

Chronic paracoccidioidomycosis in a female patient in Austria

Presented here is a case of chronic paracoccidioidomycosis that occurred in a Cuban female living in Austria and was first misdiagnosed as tuberculosis. The clinical picture was one of progressive pulmonary insufficiency with fever, weight loss and productive cough. Since antituberculous therapy was started but did not achieve a long-term clinical response, an intensive diagnostic work-up was performed. Paracoccidioides brasiliensis was then diagnosed by histopathology, serology, microbiology and molecular identification. Antifungal therapy was commenced immediately with amphotericin B (1 mg/kg/day) for 10 days, followed by voriconazole (200 mg/day po) for at least 3 months, and the lesions disappeared almost completely. This report presents the first published case of imported paracoccidioidomycosis in a female patient in Austria.

Study of bronchoalveolar lavage fluid in paracoccidioidomycosis: cytopathology and alveolar macrophage function in response to gamma interferon; comparison with blood monocytes

Patients with paracoccidioidomycosis (PCM) present marked involvement of the lungs during the course of the mycosis. The purpose of this work was to obtain bronchoalveolar lavage (BAL) fluid from these patients to study the cytopathology, TNF levels and the oxidative and fungicidal response of alveolar macrophages (AMs) to in vitro incubation with recombinant IFN-gamma. To compare the lung and blood compartments, these determinations were also made in plasma and blood monocytes (BMs) obtained from the same patients. The cytopathology of BAL fluid revealed a predominance of macrophages, but with the presence of neutrophil exudation, and rare lymphocytes and epithelioid and giant cells. Comparison of the oxidative status and fungicidal activity of AMs and circulating BMs demonstrated that both cell types are highly activated for these two functions when compared to control cells. However, TNF levels were higher in BAL fluid than in plasma. The possible mechanisms involved in the hyperresponsiveness of cells from PCM patients are discussed.

[Paracoccidioidomycosis: a clinical and epidemiological study of 422 cases observed in Mato Grosso do Sul]

Clinical and epidemiological features of 422 cases of paracoccidioidomycosis attended at University Hospital of Universidade Federal de Mato Grosso do Sul (Campo Grande, Mato Grosso do Sul, Brazil) from January 1980 to August 1999, were analysed. The mean age was 43.4 years old and the male: female ratio was 10:1. Nearly half (45.5%) of the patients were agricultural workers at the moment of diagnosis. In the acute/subacute form (juvenile type) the phagocytic-monocytic system was very much impaired and mainly marked by lymphadenopathy (95.4%), hepatomegaly (40%), splenomegaly (23.1%). The chronic form (adult type) presents more lesions in oropharynx (66.4%), dysphonia (31.4%) and cough (50.7%). Mycological diagnosis was obtained by direct microscopy of wet mounts in 185/365 (50.7%) patients and by histopathological examination of biopsies in 294/302 (97.3%) patients. The treatment of choice was Sulfamethoxazole/ trimethoprim (Co-trimoxazole), used in 90.3% patients. Sequelae occurred in 30.3% and death in 7.6% of the cases.

The oral route in the pathogenesis of paracoccidioidomycosis: an experimental study in BALB/c mice infected with P. brasiliensis conidia

Due to the high frequency of oral mucosal lesions observed in paracoccidioidomycosis patients, it was advocated that the infection was acquired by the traumatic implantation of the etiologic agent Paracoccidioides brasiliensis. Although at present this theory is considered invalid, it has not yet been excluded in experimental studies. In order to determine if intra-oral inoculation could explain the pathogenesis of paracoccidioidomycosis, 64 BALB/c mice were inoculated intra-orally with 850.000 viable P. brasiliensis conidia into the mandibular body. Animals were sacrificed at various time intervals up to 20 weeks and cultures were made from gingiva, lungs, spleen, and liver. Additionally, histopathological studies of the mandibular body were also performed. P. brasiliensis was isolated from all gingival tissues during the interval 24-72 h, indicating that the infection was active. During the 5-10 week period, the infection appeared to have been controlled at the inoculation site as cultures showed a significant reduction in colony forming units (CFU); however, at the 15-20 week period such control was lost and the fungus was recovered once more. Dissemination to other body sites was rare; thus, the lungs were involved in just one animal (2%), the liver in two (3%) and the spleen in seven (11%). The infection became established as proven by positive organ cultures, but the dissemination pattern did not correspond to the one observed in humans. Based on these findings, the intra-oral traumatic route does not appear to mimic the natural history of paracoccidioidomycosis.

Paracoccidioidomycosis in children in the state of Rio de Janeiro (Brazil). Geographic distribution and the study of a "reservarea"

Thirty six cases of acute disseminated paracoccidioidomycosis in 3 to 12 year-old children, natives of the state of Rio de Janeiro, were seen in the period 1981-1996. All patients were residents in the rural region of 15 counties, scattered on the Southwestern part of this state. The rural region of two neighboring counties, where 16 cases (44.4%) occurred, was visited. It exhibited the environmental conditions that are considered favorable to the survival of P. brasiliensis. The most important of these conditions, abundant watercourses and autochthonous forest, are distributed on well defined and limited areas, in which the dwellings are also localized. Probably, a careful epidemiological study of forthcoming cases of the disease in children may facilitate the search for the micro-niche of the fungus.

Paracoccidioidomycosis associated with acquired immunodeficiency syndrome. Report of seven cases

We report the clinical findings and evolution of seven patients (five men and two women), the majority of them intravenous drug users, with paracoccidioidomycosis associated to acquired immunodeficiency syndrome (AIDS). In four of the patients the paracoccidioidomycosis was restricted to the lung and in the three others was generalized with cutaneous involvement. Only two of them had lived recently in rural area, an indication of the possible reactivation of latent focal infection in the other five patients. The recognition of the role of cell-mediated immunity in host defense against Paracoccidioides brasiliensis leds to the prediction of a growing occurrence of the paracoccidioidomycosis-AIDS association in areas that are endemic for these diseases.

Infection and apparent invasion of Vero cells by Paracoccidioides brasiliensis

Paracoccidioides brasiliensis probably uses many different mechanisms to establish itself in the host and cause disease. In this work, we assess an in vitro model system which uses cultured mammalian cells to investigate the virulence factors of P. brasiliensis. We were able to demonstrate an invasion process of the yeast form of this fungus in Vero cell cultures. We deduced that the overall invasive process involved three steps: adhesion, followed by invasion of individual epithelial cells and spread to adjacent cells.

Paracoccidioidomycosis: an update

This review summarizes knowledge on various aspects of paracoccidioidomycosis. Mycelial propagules, chlamydospores, and arthroconidia exhibit thermal dimorphism; arthroconidia are infectious in animals and, by electron microscopy, appear well provided for survival. The mycelial-to-yeast-phase transformation requires a strict control of glucan synthesis probably mediated by membrane enzymes. Hormonal influences on the transformation of the fungus (mycelium or conidium to yeast phase) have been demonstrated. Estrogen-binding proteins have been detected in the fungal cytosol, and during the transformation novel proteins are produced as a result of estradiol incorporation. Clinical forms have been better defined on the basis of better experimental models. Emphasis has been placed on the lungs as the portal of entry and on the existence of silent pulmonary infections. A specific Paracoccidioides brasiliensis antigen, the 43-kDa glycoprotein (Gp43), has been identified, characterized, and cloned. This has led to improved reproducibility and specificity of serologic tests. The depression of cell-mediated immune responses has been associated with severe disease in humans and in the experimental host. T-cell subsets in patients' tissues were characterized by means of monoclonal antibodies, and a reduced CD4/CD8 ratio was demonstrated. This has been related to alterations in lymphokine and tumor necrosis factor production, production of antigen-antibody complexes, etc. Amphotericin B has provided effective therapy. Azole derivatives have also improved prognosis and facilitated therapy. Itraconazole is presently the drug of choice, yet incapacitating sequelae (mainly pulmonary fibrosis) still constitute major problems.

Placental involvement in paracoccidioidomycosis

A case of juvenile-type paracoccidioidomycosis in a pregnant woman is reported. The disease pre-dated pregnancy and antifungal treatment was being administered when she became pregnant. A premature male infant was delivered with no evidence of infection. Microscopic examination of the placenta showed numerous Paracoccidioides brasiliensis yeast forms in the intervillous space, enmeshed in a macrophagic-phagocytic reaction, with damage of the trophoblastic layer. Placental transfer of specific P. brasiliensis antibodies was demonstrated.

Studies on the relationship between the estrous cycle of BALB/c mice and their resistance to Paracoccidioides brasiliensis infection

A relationship between the estrous cycle and non-specific host resistance to Paracoccidiodes brasiliensis yeast cells was examined by using both sexes of adult BALB/c mice. They were divided into 6 groups, including a male group and females at proestrus, estrus, metestrus-I, metestrus-II and diestrus. The mice received yeast cells through three different inoculation routes; intravenous, intraperitoneal and intratracheal. In all of the inoculation routes, the clearance of the yeast cells was influenced by the estrous cycle. The female mice at estrus, which might have high blood estrogen levels, showed a marked clearance of the yeast cells from the blood, peritoneal cavity and lungs. These results suggested that non-specific host resistance to the yeast cells was enhanced by estrogen. All female groups inoculated by the three routes showed higher clearance of the yeast cells than the male group.

[Pulmonary lymph node in acute juvenile paracoccidioidomycosis (a case report)]

The primary complex like Ghon was observed in a child's clinical roentgenographic study. C.S., white, male, 6 years old, was born in Curitiba (PR), Brazil and living in Guaratingueta (SP), Brazil, developed "common cold", bimodal diary fever, chills, shake and sweats. Dyspnea, cough with general lymphadenopathy. Foot and right shoulder arthralgias. Six months ago visited a cave, equitation practice, dog and cat contacts and no transfusion, frontal sweats, fever (38.4 degrees C). T.A. was 8/6, tachycardia in generalized lymphadenopathy. Cardiopulmonary system was normal, mesogastric tumoral mass, hepatosplenomegaly and no ascites. Bone marrow with eosinophilia; nodule demonstrated presence of P. brasiliensis, hypoalbuminemia; hyperglobulinemia; anemia; leukocytosis with eosinophilia. Immunodiffusion with exoantigen 43 kd of P. brasiliensis was 1/32. Primary complex like Ghon was observed in interstitial pneumonia followed by mediastinal and mesogastric mass (35 to 40 days). Clavicular osteolytic lesions (45 to 60 days) appeared during paracoccidioidomycosis therapy. Recovery was observed 2 months after treatment of acute infantile paracoccidioidomycosis.

Studies on the relationship between paracoccidioidomycosis in ddY mice and their estrous cycle

The relationship between paracoccidioidomycosis in ddY mouse and its estrous cycle was studied. Adult ddY mice of both sexes were used as experimental animals. Estrous cycle of female mice was examined before inoculation of Paracoccidioides brasiliensis yeast cells and mice were divided into 5 groups such as proestrus, estrus, metestrus-I, metestrus-II and diestrus. Each mouse was inoculated intravenously with 10(6) P. brasiliensis yeast cell units and sacrificed on day 28 after inoculation. Their internal organs were cultured, and in addition, their histopathologies were studied. As a result, there was no difference in the organ cultures among the male and the female mice of 5 groups. However, histopathologically, the female groups at estrus, metestrus-I and metestrus-II were affected more severely than the male group, and the susceptibility of the female mice to the fungus was closely related to their estrous cycles.

Inapparent lung involvement in patients with the subacute juvenile type of paracoccidioidomycosis

Three patients with the diagnosis of subacute juvenile paracoccidioidomycosis who, at the time of their first visit, had no signs or symptoms of lung involvement were studied. Initially the diagnosis was confirmed by the observation of P. brasiliensis in biopsy material obtained from clinically involved lymphadenopathies. The lung X-rays done in all patients, did not reveal pathologic changes, although it was possible to observe and isolate the fungus from sputum samples obtained from the three patients. This fact reinforces the pulmonary genesis of the mycosis and proofs the existence of a pulmonary primary infection, even in patients with the juvenile manifestations, in whom the lung component is obscured by the predominant lymph node involvement.

Experimental murine paracoccidiodomycosis induced by the inhalation of conidia

Adult BALB/c mice of both sexes were infected intranasally with 10(6) viable P. brasiliensis conidia. Animals were sacrificed at intervals up to 6 months and studied by histopathology and organ cultures. At the time of challenge lung sections showed that instilled conidia had reached the alveoli; at 12 h such conidia were transforming into yeast cells, with multiple buds appearing by 18 h. Initially, the cellular infiltrate was composed of polymorphonuclear leukocytes; 6 days later, lymphocytes, plasmocytes and macrophages predominated. Multinucleated giant cells appeared only after 6 weeks. The rate of pulmonary infection as determined by organ culture was high (82 of the 83 mice studied). The experimental infection was progressive as indicated by increasing numbers of viable fungi with time. The results of this study demonstrate that the conidia produced by P. brasiliensis mycelial form are infectious, producing active disease in healthy animals.

Host-parasite relationships in paracoccidioidomycosis

A viewpoint of host-parasite relationships in paracoccidioidomycosis is presented. The characteristics of the fungus which are important to the host-parasite interaction are discussed. Aspects of inhibition of mycelium-to-yeast transformation by estrogens acting at receptors on the fungal wall and in the cytoplasm, and the role of polysaccharide components of the cell wall in virulence are reviewed. The natural mechanisms of host defense are also examined, including phagocytosis, complement system, natural-killer cells and genetic control of resistance and susceptibility. Finally, a discussion of granuloma morphogenesis and its relationship to the humoral and cellular anti-P. brasiliensis immune response is presented.

Paracoccidioidomycosis in a four-year-old boy

A case of fatal, generalized paracoccidioidomycosis is described in a four-year-old urban dwelling child. Marked lymphadenopathy, hepatosplenomegaly and an abdominal mass were the main clinical manifestations. The diagnosis was established by histopathological studies and culture. The authors comment on the rarity of this infection in children less than 7 years of age and on the importance of considering this pathology in the differential diagnosis of malignant non-Hodgkin lymphoma and tuberculosis, in children.

Pathology of the human pulmonary paracoccidioidomycosis

Lungs of twelve patients with chronic paracoccidioidomycosis (Pb) were studied in an attempt to understand the pathogenesis of the pulmonary disease. Ribbons of the lung parenchyma including the hilar region and directed towards apical, basal and lateral regions were subdivided into sections from the hilar, intermediate and peripheral segments. The following histopathological reactions directly or indirectly related to P. brasiliensis were described and analysed in relation to the number of slides studied and the pulmonary region involved: pneumonic reaction; early granulomatous formation; mature and healed granulomata; mixed pattern (early and mature granuloma in the same pulmonary area visualized in the slide); pulmonary fibrosis. It was concluded that chronic pulmonary Pb is a recurrent disease affecting equally both lungs. Fibrosis was connected mainly with the progressive evolution of the granulomata towards cicatrization and to a lesser degree probably to a direct induction by the fungi. Based chiefly on the tendency of the fibrosis to run around bronchi and to make up septa interconnecting bronchi and vessels it was hipothesized that these findings were the result of a previous chronic specific lymphangitis by the fungi. Hilar fibrosis would be the result of this lymphangitis and/or of the progression of the specific granulomatous reaction seen in the hilar lymph nodes. Non specific forms of arteritis and areas of destructive emphysema related to granulomatous inflammation and fibrosis were described. Three cases developed pulmonary hypertension.

Paracoccidioidomycosis in children with different skeletal involvement

The rarity of paracoccidioidomycosis in childhood prompted us to report two cases with different clinical and radiological skeletal involvement. The number of osteolytic lesions, the presence of periosteal reaction and the finding of Paracoccidioides brasiliensis in biopsy specimens, were distinctive features in both cases.

[Progressive subacute paracoccidioidomycosis. Treatment of a patient with amphotericin B and parenteral feeding]

Os Autores descrevem um caso de paracoccidioidomicose subaguda progressiva, com quadro clínico sugestivo de síndrome de má absorção, em que o doente não se beneficiara apenas com o tratamento antifúngico convencional. Ao se introduzir como medida auxiliar a nutrição parenteral houve evidente melhora clínica e laboratorial. Desta maneira os Autores propõe o uso associado da nutrição parenteral no tratamento de doentes com esta forma clínica de paracoccidioidomicose.

Serology of paracoccidioidomycosis. I. Evaluation of the indirect immunofluorescent test

The purposes of the present work were: i) to study the positivity indices and compare titers obtained with the indirect immunofluorescence (II), tube precipitation (TP), complement fixation (CF) and double immunodiffusion on agar gel (ID) tests in the sera of 196 patients with paracoccidioidomycosis before treatment, and ii) to compare the initial titers of II with those obtained 1 year or more after treatment. II was the most sensitive serologic reaction (85.2%), and the positivity indices for CF, ID and TP were 67.7%, 66.0% and 50.0%, respectively. The sera tended to show parallel mean titers in II, CF and TP tests. One year after treatment there was a fall in titers of II in 66.2% of patients. The data, taken as a whole, demonstrate the usefulness of the indirect immunofluorescent test and the importance of using 2 or more serologic tests for the diagnosis and monitoring of patients with paracoccidioidomycosis.

Correlation between cell-mediated immunity and clinical forms of paracoccidioidomycosis

Cellular immune response to specific and non-specific stimulants was investigated, both in vivo and in vitro, in 29 healthy controls and in 53 previously untreated patients with the chronic isolated organic form (CIOF), the chronic mixed form (CMF) and the acute progressive form (APF) of paracoccidioidomycosis. The study included skin tests to Paracoccidioides brasiliensis antigen (PbAg) and phytohaemagglutinin (PHA), DNCB sensitization, determination of T lymphocytes and complement rosette-forming cells, lymphocyte transformation and leucocyte migration inhibition tests using PbAg and PHA. Patients displayed staggered cutaneous response to PHA and to PbAg, with marked decrease in intensity in the APF group. DNCB sensitization test and proliferative response of lymphocytes to PHA and PbAg were severely depressed in most of the patients. Leucocyte migration inhibition indices to PbAg were highly positive, while response to PHA was slightly decreased regardless of the clinical form. The number of T lymphocytes was reduced in most of patients and in them the number of complement-rosette forming cells was normal. The distribution of patients according to a suppression index, based in the results of the tests employed, revealed a tendency towards an increased degree of cellular immunosuppression from the least severe (CIOF) to the most severe (APF) clinical form of the disease. On the whole, the present study demonstrated a gamut of immunological reactivity in paracoccidioidomycosis.

In vitro effects of natural killer cells against Paracoccidioides brasiliensis yeast phase

Recently, data have been reported suggesting natural killer (NK) cells may function in natural resistance against a fungus, Cryptococcus neoformans. The primary objective of this study was to examine the reactivity of murine splenic cells against another fungus, Paracoccidioides brasiliensis. Levels of NK activity in effector cell pools were varied by: (i) removing nylon wool-adherent cells, (ii) fractionating splenic cells on Percoll discontinuous gradients, (iii) using old and young effector cell donor mice, (iv) using donors from different strains, and (v) pretreating donors with NK-augmenting and -depressing agents. The various effector cell pools were simultaneously used in the 4-h 51Cr release assay with YAC-1 targets to determine the NK reactivity and in the in vitro growth inhibition assay against P. brasiliensis yeast phase targets. In each case, the level of NK reactivity correlated with the ability of the effector cells to inhibit the in vitro growth of P. brasiliensis. NK activity and P. brasiliensis growth-inhibiting ability could be augmented by fractionation of splenic cells through nylon wool or Percoll gradients. The effector cells responsible for the NK activity and P. brasiliensis growth inhibition were characterized as being nylon wool nonadherent, being found in the low-density fractions from Percoll discontinuous gradients, and having no detectable Thy-1 antigen or immunoglobulin but having asialo GM1 on their surface. These data support the contention that NK or NK-like cells are responsible for limiting the in vitro growth of P. brasiliensis.

Serology of paracoccidioidomycosis. II. Correlation between class-specific antibodies and clinical forms of the disease

Untreated and previously treated patients with paracoccidioidomycosis were studied for: (i) serum levels of total IgG, IgM and IgA immunoglobulins, by radial immunodiffusion and Paracoccidioides brasiliensis (Pb) antibodies, by indirect immunofluorescence; (ii) correlation between their levels with the clinical forms of the disease; (iii) correlation between the serum titres obtained by tube precipitin with those of anti-Pb IgG, IgM and IgA. In the untreated group, serum IgG levels were significantly increased in patients with the more systemic forms of the disease, especially the acute progressive form. Serum IgA levels were significantly increased in all patients with no statistical difference between clinical forms. Serum IgM levels were normal in all patients. Anti-Pb IgG, IgA and IgM were detected in 97.5%, 32.5% and 45.0% of all cases, respectively. There was a sharp tendency towards higher levels of anti-Pb IgG among those with the acute progressive form (83.4%) in relation to the chronic, more localized forms, mixed form (68.0%) and isolated organic form (55.5%). In the untreated and previously treated group sera, there was positive correlation between the level of anti-Pb IgG and positivity for the tube precipitin test, suggesting that the precipitin-type antibodies are of the IgG class. Broadly, the present data demonstrate a polyclonal activation of the humoral immune system in paracoccidioidomycosis, with a positive relationship between serological results and severity of the disease.

Spontaneous regression of pulmonary paracoccidioidomycosis. Report of a case

A case of pulmonary paracoccidioidomycosis with spontaneous regression of the roentgenologic lesions, is reported. Regression of lesions took place within ten weeks, with the original infiltrates being replaced by fibrotic lines. The implication of this finding in the pathogenesis of paracoccidioidomycosis is analyzed.

Paracoccidioidomicose pulmonar assintomática e regressiva, com posterior disseminação: relato de um caso

É relatado o caso de um homem aparentemente sadio no qual uma abreugrafia de rotina evidenciou lesões pulmonares. Enquanto se buscava a etiologia, as lesões radiológicas foram regredindo espontaneamente até restar apenas fibrose. Por apresentar linhas de precipitação específicas frente à paracoccidioidina na prova de imunodifusão dupla em gel de agar, o paciente foi revisto 3 meses após. Nesta ocasião, persistindo a positividaàe da sorologia e a radiografia de tórax normal, surgiu uma lesão labial, na qual, ao exame microscópico, foi possível demonstrar a presença do Paracoccidioides brasiliensis. Os autores ressaltam as dificuldades diagnosticas do caso e o correlacionam com as formas clinicas da doença.

Granuloma formation and killing functions of granuloma in congenitally athymic nude mice infected with Blastomyces dermatitidis and Paracoccidioides brasiliensis

We did this experiment to clarify the mechanism of granuloma formation and the killing functions of granuloma in nude mice against Blastomyces dermatitidis and Paracoccidioides brasiliensis infections. B. dermatitidis A-295 and P. brasiliensis B-1183 were the cultures used. Congenitally athymic nude (nu/nu) mice and their heterozygous (nu/+) littermates of BALB/c background were the test animals. From culture A-295, 0.1% and 1% cell suspensions (wet weight) were prepared and from culture B-1183 0.2% and 2% cells suspensions were prepared. Ten nu/+ and 10 nu/nu mice were allotted to each of four cell suspensions. For experimental blastomycosis each mouse was inoculated intravenously with 0.2 ml of the cell suspension of A-295 and for experimental paracoccidioidomycosis, with 0.15 ml of the cell suspension of B-1183. Two mice from each of the four groups were killed at 5, 8, 12, 18 and 25 days after inoculation, and histopathologic sections, stained with H&E or by PAS, were prepared from various internal organs. In the nu/nu mice inoculated with B. dermatitidis A-295 granuloma was formed in the brain tissue after the 12th day. However, mononuclear cells, which formed the granuloma, did not kill the fungal cells, and the fungal cells continued to multiply in the granuloma. On the other hand, in the heart, kidney and fat tissue, their histopathological findings after the 18th day were clumps of fungal cells with slight cell reactions. In these organs the exertion of cell-mediated immunity was necessary for granuloma formation against the fungal infection. In the nu/nu mice infected with P. brasiliensis B-1183, granuloma appeared in the brain and kidney after the 18th day and fungal cells continued to multiply within the granuloma as well as in those inoculated with culture A-295. These results show that the exertion of cell-mediated immunity plays an important role in the mouse's defense mechanisms against these fungal infections. We assume that the defense mechanisms of immunocompetent mice against B. dermatitidis or P. brasiliensis infection consist chiefly of two steps: in the first step phagocytosis by PMNs occurs and in the second step cell-mediated immunity enters into play.

Experimental paracoccidioidomycosis in immunosuppressed mice

Mice were immunosuppressed by means of wholebody irradiation or cyclophosphamide, in order to investigate the influence on the initial phase of infection induced by a strain of the fungus, Paracoccidioides brasiliensis, in the yeast phase and inoculated intraperitoneally. A group of mice was irradiated with 600 rad (cobalt gamma-irradiation) 24 h before infection. Two groups were treated with cyclophosphamide (200 mg/kg intravenously), one two days before, and the other, one day after infection. A control group received the fungus, but no radiation or cyclophosphamide. All animals developed lesions at the site of inoculation. Metastatic lesions were observed in 100% of the animals in the irradiated group, 67% in each of the cyclophosphamide-treated groups and 33% in the control group. These lesions were found both in the liver and lungs, being more numerous in the irradiated group, followed by the cyclophosphamide-treated group in which the drug was given after the infection; they were slight in both viscera in the other cyclophosphamide-treated group and also slight in the liver and absent in the lungs of the controls.

Experimental pulmonary paracoccidioidomycosis in mice: morphology and correlation of lesions with humoral and cellular immune response

The present paper describes a murine model for pulmonary paracoccidioidomycosis injecting 6 X 10(5) yeast forms of Paracoccidioides brasiliensis (Pb) by the direct intratracheal route. The sequential histopathology of lung and dissemination lesions together with humoral (immunodiffusion test) and cellular immune response (footpad test and macrophage inhibition factor assay - MIF assay) were investigated since the 1st to the 360th day after infection. All infected animal showed pulmonary Pbmycosis up to Day 30; onwards the lesions subsided being found only in one mouse at Day 360. Dissemination lesions were observed in paratracheal and cervical lymph nodes in 9 out of 68 infected animals. Histologically early lesions were rich in polymorphonuclear cells and evolved to a macrophage desquamative pneumonitis at Day 15 and to typical epithelioid granulomata from Day 30 up to Day 360. Specific precipitating antibodies were first detected 15 days after infection, peaked from Day 30 to 60 and were not observed at Day 360. Significant cell-mediated immunity to Pb was noted at Day 15 with the peak reaction at Day 60 and 90. The intratracheal route represents a highly effective way of infecting mouse with Pb. This experimental pulmonary Pbmycosis is a granulomatous inflammation which courses with specific humoral and cellular immune response. It may be a good tool for further investigation in the pathogenesis and natural history of the disease.

The gamut of progressive pulmonary paracoccidioidomycosis

Paracoccidioidomycosis is an important Latin American endemy. The lung is the portal of entrance of the infection and the lesions are confined to this organ in, at least, 30 per cent of the progressive cases. Twelve case histories of patients with the progressive pulmonary form are presented in order to illustrate the repetitious clinical manifestations but the large variety of radiological presentations. The mycologic diagnosis is also emphasized.

Studies on plating efficiency and estimation of viability of suspensions of Paracoccidioides brasiliensis yeast cells

Mild sonication was used to obtain single cell suspensions of Paracoccidioides brasiliensis. These cells were intact by microscopic criteria. Direct cell counts in a given inoculum and colony formation on various media were used to determine plating efficiency. Sonicated and nonsonicated cell suspensions were used to study plating efficiency and to estimated viability by means of vital dyes. Methylene blue Erythrosin B, and Janus green were unreliable when used with P. brasiliensis, but vital dyes were accurate when tested with Candida albicans. Acridine orange gave more meaningful results of viability. Estimates of viability, however, changed significantly as a result of relatively minor alterations in the composition of the suspending medium. In initial experiments, the plating efficiency of P. brasiliensis was dismally low. It descended abruptly with increasing dilution of inoculum. Efficiency was much improved if horse serum was added to brain heart infusion plates or if glucose glycine yeast extract (GGY) plates were incubated at room temperature and mycelial colonies were counted. With the technique we report, current plating efficiency of sonicated suspensions is of the order of 25%. Our results and procedures have an important bearing upon those studies concerned with in vitro killing of P. brasiliensis in suspensions or with isolating this fungus from clinical or environmental specimens.

Blastomycosis of the colon resembling clinically ulcerative colitis

An 8 year old Brazilian girl had an infection, apparently confined to the large intestine, with Paracoccidioides brasiliensis. The symptoms were diarrhoea with fresh blood and mucus, severe malnutrition, and a spastic and ulcerated colon. She is making good progress on co-trimoxazole.

Progressive pulmonary paracoccidioidomycosis a study of 34 cases observed in Rio Grande do Sul (Brazil)

Data on 34 patients with progressive pulmonary paracoccidioi domycosis seen in the State of Rio Grande do Sul (Brazil) are reviewed. Clinical manifestations were similar to those of a prolonged or a recurrent undifferentiated respiratory infection. Roentgenographic findings were also non-characteristic. A mycologic diagnosis was readily made when sputum was available.